Malicious PDF — malware analysis report

Static analysis result for SHA-256 a289f262d3f8b47b…

MALICIOUS

PDF

101.5 KB Created: 2021-05-22 07:09:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 12f4f197408ad1a44df586fd43962bef SHA-1: bbdd48691f3789b787ebb6409df22f8e72a88c28 SHA-256: a289f262d3f8b47b32db8879f6acf9e0dc82999020a3800863ff4fa5742cbdc1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains a large number of external links, many of which point to other PDF files, suggesting a link farm or SEO spamming operation. One of the embedded URLs, https://nipisod.ru/strik?utm_term=which+washer+brand+is+most+reliable, is presented as a search result, likely to trick users into clicking. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://nipisod.ru/strik?utm_term=which+washer+brand+is+most+reliable
    • https://cdn-cms.f-static.net/uploads/4426945/normal_6009fe97b4db0.pdf
    • https://cdn-cms.f-static.net/uploads/4487641/normal_601a18f3957f5.pdf
    • https://cdn-cms.f-static.net/uploads/4409616/normal_600c68309e29e.pdf
    • https://cdn-cms.f-static.net/uploads/4530712/normal_604fab1b7a451.pdf
    • https://static.s123-cdn-static.com/uploads/4374188/normal_5ff829372c2fa.pdf
    • https://xewuligatojijow.weebly.com/uploads/1/3/5/3/135395235/febofe-nomasadupa-timubakul-lopapezominox.pdf
    • https://kojezuduw.weebly.com/uploads/1/3/5/3/135326104/mapabogobesubururaru.pdf
    • https://suxewanevot.weebly.com/uploads/1/3/4/5/134595646/vanefojikaja_fidovuk_rewuwiged.pdf
    • https://vofodiwe.weebly.com/uploads/1/3/5/3/135350815/vagefapasabapek.pdf
    • https://mijagipiked.weebly.com/uploads/1/3/4/5/134524971/xapiredi.pdf
    • https://redorofi.weebly.com/uploads/1/3/5/3/135383823/8130766.pdf
    • https://cdn-cms.f-static.net/uploads/4367313/normal_600ca744bcdf9.pdf
    • https://static.s123-cdn-static.com/uploads/4482863/normal_5ffa86f2ab05d.pdf
    • https://cdn-cms.f-static.net/uploads/4420025/normal_6022bc4d173e6.pdf
    • https://cdn-cms.f-static.net/uploads/4491151/normal_604e1645006f6.pdf
    • https://wazolupagod.weebly.com/uploads/1/3/0/7/130775763/5911062.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/paxuvagal/netevejunivekuleno.pdf
    • https://s3.amazonaws.com/zunaduxa/dupenitirujudexosigan.pdf
    • https://s3.amazonaws.com/pezofut/xamilinarojonogiges.pdf
    • https://s3.amazonaws.com/wofaxil/6725254256.pdf
    • https://s3.amazonaws.com/jinotugiwomo/7979726824.pdf
    • https://s3.amazonaws.com/vunizi/17323215556.pdf
    • https://s3.amazonaws.com/jotizifime/cien_aos_de_soledad_audiolibro_capitulo_17.pdf
    • https://s3.amazonaws.com/tawosutosuxi/voltage_controlled_oscillator_using_ic_555.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00014e43.bin
daa6b024f631585e48a3861a61df03beed22d4f3a358f1050aa08505f91052d0
pdf-font-stream PDF embedded font (sfnt) at offset 0x14E43 5424 bytes
font_01_sfnt_off0001609a.bin
5ccaee8e887ce9040191a6a9df3de97eb4be949b01a749637a2c7166b0d7f343
pdf-font-stream PDF embedded font (sfnt) at offset 0x1609A 11564 bytes